No — 72 DPI is not best for web images, because DPI does nothing on the web. Browsers lay images out in pixels and ignore the DPI/PPI field entirely; a photo saved at 72dpi and the same photo saved at 300dpi are identical on screen. The only “resolution” the web understands is pixel dimensions.

What the DPI field actually is

DPI (more precisely PPI — pixels per inch) is a number in the file’s metadata that tells print software how densely to place pixels on paper. It is a display instruction for a medium that doesn’t exist on screens. When a phone camera writes “72 dpi” into EXIF, it’s filling in a mandatory spec field, not describing anything about the sensor.

Property	Matters on web?	Matters in print?
Pixel dimensions (e.g. 2400×1600)	Yes — the only “resolution”	Yes — decides max print size
DPI/PPI metadata tag	No — ignored by browsers	Yes — pixels ÷ DPI = physical size
File size (KB)	Yes — load speed	No — printers don’t care
Display density (retina = 2×)	Yes — export at 2× display px	n/a

The numbers that do matter on screen

“Resolution” for the web means two concrete things:

• Export at ~2× display pixels. An image shown at 1200px wide wants a 2400px file, because high-density screens draw two physical pixels per CSS pixel. That’s the whole retina story — there’s no DPI setting involved at any step.
• Budget the KB. Pixel count × format × quality decides file weight, and file weight decides speed. How much to compress has the per-use budgets; the compressor handles the mechanics.

Where 300 DPI is real advice

Print is the one place the number does work: print size = pixels ÷ 300. A 3000px-wide photo gives a clean 10-inch-wide print; at 72dpi it would claim a 41-inch print at unusable quality — same pixels, different instruction. So the honest version of the old rule is: 72 and 300 are equally meaningless on screen; 300 at final size is the standard for paper.

If your image is headed for an upload form rather than a printer, forget DPI exists and check the two numbers that count — pixel dimensions and KB. The format guide covers which codec preserves what once those are set.

Frequently asked questions

Does DPI matter for images on a website?

No. Browsers render images by pixel count, not by the DPI/PPI field stored in the file's metadata. A 1200×800 image saved at 72dpi and the identical image saved at 300dpi display at the same size, look the same, and are nearly the same file size — the DPI value is a hint for print software, and nothing on the web reads it.

Why do people say images for the web should be 72 DPI?

It's a fossil from early desktop publishing. Screens in the 1990s really did render ~72 pixels per inch, so 'screen resolution = 72dpi' was briefly true advice. Modern displays run 110–220+ physical pixels per inch, and browsers never consulted the DPI field anyway. The advice survived decades after the reason for it disappeared.

What resolution should web images be, if not DPI?

Pixel dimensions: roughly 2× the largest size the image will display at. A hero shown 1400px wide should be exported at ~2800px; a thumbnail shown at 300px should be ~600px. That 2× factor covers high-density (retina) screens, which pack 2 physical pixels per CSS pixel. The compression guide has budgets per use case.

My camera saves photos at 72 DPI — should I change it?

There's nothing to change. Cameras write 72 (or 240, or 300) into EXIF as a placeholder because the field is mandatory in the spec — it's not a quality setting and it doesn't describe your sensor. Your 24-megapixel file is 6000×4000 pixels whether the tag says 72 or 600. Worry about pixels and file size; the DPI tag is noise.

When does 300 DPI actually matter?

Print — and only print. A 300dpi image prints its pixels at 300 per inch, so print size = pixels ÷ 300: a 3000px-wide photo yields a 10-inch-wide print. If your image will live on paper (flyers, photo prints, magazine submissions), 300dpi at final size is the standard target. For anything displayed on a screen, the number is meaningless.

Does a higher DPI make a bigger file?

Practically no — changing only the DPI tag edits a few bytes of metadata. What makes files big is pixel dimensions and compression settings. If a '300dpi version' of an image is much larger than the '72dpi version', someone resampled it — added real pixels — rather than just changing the tag. Resampling up doesn't add detail; it adds bytes.